Re: [PATCH v16 5/7] spi: pxa2xx: disable DMA for Apple MacBook8,1
Andy Shevchenko <[email protected]> Tue, 21 Jul 2026 23:28:29 +0300
| Newsgroups | org.kernel.vger.linux-spi,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel |
|---|---|
| Organization | Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo |
| Message-ID | <[email protected]> |
On Tue, Jul 21, 2026 at 11:26:27PM +0800, Shih-Yuan Lee (FourDollars) wrote: > On Tue, Jul 21, 2026 at 11:05 PM Mark Brown <[email protected]> wrote: ... > Actually, I was just following Lukas's suggestion to modify > drivers/dma/dw/pci.c to do a quick proof-of-concept test, and I used > an AI assistant to help me write and deploy the driver quirk code. > > I have previous experience with the Initrd ACPI Table Override > mechanism, so I can definitely try that on my machine next to see if > we can get DMA working properly by aligning the PCI routing and DMAR > mapping correctly). > output. For old hardware (before Skylake) LPSS DMA interrupt line is defined in two places: DSDT (and/or PCI) and CSRT. Changing in one might not help as CSRT may have something different. Check drivers/dma/acpi-dma.c acpi_dma_parse_resource_group(). -- With Best Regards, Andy Shevchenko